Gastroesophageal reflux disease (GERD) is a chronic condition caused by the failure of the anti-reflux barrier located at the gastroesophageal junction to keep the contents of the stomach from splashing into the esophagus. The splashing is known as gastroesophageal reflux. The stomach acid is designed to digest meat, and will digest esophageal tissue when persistently splashed into the esophagus.
FIG. 1 is a front cross-sectional view of the esophageal-gastro-intestinal tract 40 from a lower portion of the esophagus 41 to the duodenum 42. The stomach 43 is characterized by the greater curvature 44 on the anatomical left side and the lesser curvature 45 on the anatomical right side. The fundus 46 of the greater curvature 44 forms the superior portion of the stomach 43, and traps gas and air bubbles for burping. The esophageal tract 41 enters the stomach 43 at a point below the superior portion of the fundus 46, forming a cardiac notch 47 and an acute angle with respect to the fundus 46 known as the Angle of His 57. The lower esophageal sphincter (LES) 48 is a discriminating sphincter able to distinguish between burping gas, liquids, and solids, and works in conjunction with the fundus 46 to burp. The gastroesophageal flap valve (GEFV) 49 includes a moveable portion and an opposing more stationary portion. The moveable portion of the GEFV 49 is an approximately 180 degree, semicircular, gastroesophageal flap 50 (alternatively referred to as a “normal moveable flap” or “moveable flap”) formed of tissue at the intersection between the esophagus 41 and the stomach 43. The opposing more stationary portion of the GEFV 49 comprises a portion of the lesser curvature 45 of the stomach 43 adjacent to its junction with the esophagus 41. The gastroesophageal flap 50 of the GEFV 49 principally comprises tissue adjacent to the fundus 46 portion of the stomach 43, is about 4 to 5 cm long (51) at it longest portion, and the length may taper at its anterior and posterior ends. The gastroesophageal flap 50 is partially held against the lesser curvature 45 portion of the stomach 43 by the pressure differential between the stomach 43 and the thorax, and partially by the resiliency and the anatomical structure of the GEFV 49, thus providing the valving function. The GEFV 49 is similar to a flutter valve, with the gastroesophageal flap 50 being flexible and closeable against the other more stationary side.
The esophageal tract is controlled by an upper esophageal sphincter (UES) near the mouth for swallowing, and by the LES 48 and the GEFV 49 at the stomach. The normal antireflux barrier is primarily formed by the LES 48 and the GEFV 49 acting in concert to allow food and liquid to enter the stomach, and to considerably resist reflux of stomach contents into the esophagus 48 past the gastroesophageal tissue junction 52. Tissue aboral of the gastroesophageal tissue junction 52 is generally considered part of the stomach because the tissue protected from stomach acid by its own protective mechanisms. Tissue oral of the gastroesophageal junction 52 is generally considered part of the esophagus and it is not protected from injury by prolonged exposure to stomach acid. At the gastroesophageal junction 52, the juncture of the stomach and esophageal tissues form a zigzag line, which is sometimes referred to as the “Z-line.” For the purposes of these specifications, including the claims, “stomach” means the tissue aboral of the gastroesophageal junction 52. As pressure in the stomach 43 increases, the pressure tightly closes the normal gastroesophageal flap 50 of the GEFV 49 against the lesser curve portion 45 of the stomach. The tissues are tightly opposed preventing reflux. The stomach 43 provides for burping by the diaphragm 53 pushing down on and flattening the fundus 46, temporarily resulting in the cardiac notch 47 being straightened and the Angle of His 57 becoming less acute. The normal gastroesophageal flap 50 of the GEFV 49 opens to allow the burp to pass into the esophagus 41.
FIG. 2 is a front cross-sectional view of the esophageal-gastro-intestinal tract 40 illustrating a Grade I normal appearance movable flap 50 of the GEFV 49 and a Grade IV reflux appearance gastroesophageal flap 55 of the GEFV 49. A principal reason for regurgitation associated with GERD is the mechanical failure of the deteriorated (or reflux appearance) gastroesophageal flap 55 of the GEFV 49 to close and seal against the high pressure in the stomach. Due to reasons including lifestyle, a Grade I normal gastroesophageal flap 50 of the GEFV 49 may deteriorate into a Grade IV deteriorated (or reflux appearance) gastroesophageal flap 55. The anatomical results of the deterioration include moving a portion of the esophagus 41 that includes the gastroesophageal junction 52 and LES 48 toward the mouth, straightening of the cardiac notch 47, and increasing the Angle of His 57. This effectively reshapes the anatomy aboral of the gastroesophageal junction 52 and forms a flattened fundus 56. The deteriorated gastroesophageal flap 55 illustrates a gastroesophageal flap valve 49 and cardiac notch 47 that have both significantly degraded. Dr. Hill and colleagues developed a grading system to describe the appearance of the GEFV and the likelihood that a patient will experience chronic acid reflux. L. D. Hill, et al., The gastroesophageal flap valve: in vitro and in vivo observations, Gastrointestinal Endoscopy 1996:44:541-547. Under Dr. Hill's grading system, the normal movable flap 50 of the GEFV 49 illustrates a Grade I flap valve that is the least likely to experience reflux. The deteriorated gastroesophageal flap 55 of the GEFV 49 illustrates a Grade IV flap valve that is the most likely to experience reflux. Grades II and III reflect intermediate grades of the likelihood of experiencing reflux. In the Grade IV condition with the deteriorated GEFV represented by deteriorated gastroesophageal flap 55 and the fundus 46 moved inferior, the stomach contents are presented a funnel-like opening directing the contents into the esophagus 41.
With the deteriorated gastroesophageal flap 55, the stomach contents are more likely to be regurgitated into the esophagus 41, the mouth, and even the lungs. The LES 48 by itself is relatively weak and does not provide sufficient resistance to prevent reflux or regurgitation by itself. The regurgitation is referred to as “heartburn” because the most common symptom is a burning discomfort in the chest under the breastbone. Burning discomfort in the chest and regurgitation (burping up) of sour-tasting gastric juice into the mouth are classic symptoms of gastroesophageal reflux disease (GERD). When stomach acid is regurgitated into the esophagus, it is usually cleared quickly by esophageal contractions. Heartburn (backwashing of stomach acid and bile onto the esophagus 41) results when stomach acid is frequently regurgitated into the esophagus 41, or if it is not promptly cleared. Chronic heartburn or GERD occurs because of a mechanical failure by the deteriorated gastroesophageal flap 55 of the GEFV 49 and the LES 48 to keep stomach acid and digestive juices out of the esophagus 41. The GEFV 49 and LES 48 fail to maintain the normally higher pressure in the stomach 43 and keep stomach contents out of the esophagus 41. People with a normal movable flap 50 may experience occasional transient GEFV 49 and LES 48 relaxations that lead to backwashing of stomach contents onto the esophagus 41. These transient relaxations account for most of the gastroesophageal reflux episodes and occasional symptoms in people with a normal gastroesophageal flap 50. However, because the deteriorated gastroesophageal flap 55 of GEFV 49 and the LES 48 are not mechanically able to maintain the normal pressure in the stomach 43, the stomach contents more readily and regularly bathe the esophagus 41. The esophageal contractions alone are not strong enough to adequately “strip” the stomach contents out of the esophagus 41, leading to prolonged acid and bile exposure in the esophagus. This prolonged exposure allows injury to the normal squamous lining of the esophagus to occur, resulting in esophagitis and in some people, healing of the esophagus with the development of a new lining, called Barrett's esophagus.
Complications develop for some people who have GERD. Esophagitis (inflammation of the esophagus) with erosions and ulcerations (breaks in the lining of the esophagus) can occur from repeated and prolonged acid exposure. If these breaks are deep, bleeding or scarring of the esophagus with formation of a stricture (narrowing of the esophagus) can occur. If the esophagus narrows significantly, then food sticks in the esophagus and the symptom is known as dysphagia. GERD has been shown to be one of the most important risk factors for the development of esophageal adenocarcinoma. In a subset of people who have severe GERD, if acid exposure continues, the injured squamous lining is replaced by Barrett's metaplasia (Barrett's esophagus), a precancerous lining in which esophageal adenocarcinoma can develop. To date, no one knows what causes Barrett's esophagus.
Other complications of GERD may not appear to be related to esophageal disease at all. Some people with GERD may develop recurrent pneumonia (lung infection), asthma (wheezing), or a chronic cough from acid backing up into the esophagus and all the way up through the upper esophageal sphincter into the lungs. In many instances, this occurs at night, while the person is sleeping. Occasionally, a person with severe GERD will be awakened from sleep with a choking sensation. Hoarseness can also occur due to acid reaching the vocal cords, causing a chronic inflammation or injury.
Deteriorated gastroesophageal flap 55 and GERD never improve without intervention. Both medical and surgical treatments exist for GERD. Medical therapies include antacids and proton pump inhibitors. However, the medical therapies only mask the reflux. Patients still get reflux and perhaps emphysema because of particles refluxed into the lungs. Barrett's esophagus results in about 10-15% of the GERD cases. The esophageal epithelium changes into tissue that tends to become cancerous from repeated acid washing despite the medication.
Several open laparotomy and laproscopic surgical procedures are available for treating GERD. One surgical approach is the Nissen fundoplication. The Nissen approach typically involves a 360-degree wrap of the fundus around the gastroesophageal junction 52. The procedure has a high incidence of postoperative complications. The Nissen approach creates a 360-degree moveable flap without a fixed portion. While Nissen reinforces the LES 48, it does not restore the normal movable flap 50 of GEFV 49. The patient cannot burp because the fundus 46 was used to make the repair, and may frequently experience dysphagia. Another surgical approach to treating GERD is the Belsey Mark IV (Belsey) fundoplication. The Belsey procedure involves creating a valve by suturing a portion of the stomach 43 to an anterior surface of the esophagus 41. It reduces some of the postoperative complications encountered with the Nissen fundoplication, but still does not restore the normal movable flap 50 of GEFV 49. None of these procedures fully restores the normal anatomical anatomy or produces a normally functioning gastroesophageal junction. Another surgical approach is the Hill repair. In the Hill repair procedure, the gastroesophageal junction 52 is anchored to the posterior abdominal areas, and a 180-degree valve is created by a system of sutures. The Hill procedure restores the moveable flap 50, the cardiac notch 47 and the Angle of His 57. However, all of these surgical procedures are very invasive, regardless of whether done as a laproscopic or an open procedure.
New, less surgically invasive approaches to treating GERD involve transoral endoscopic procedures. One procedure contemplates a machine device with robotic arms that is inserted transorally into the stomach 43. While observing through an endoscope, a endoscopist guides the machine within the stomach 43 to engage a portion of the fundus 46 with a corkscrew-like device on one arm. The arm then pulls on the engaged portion to create a flap of tissue near the deteriorated gastroesophageal flap 55. Another arm of the machine pinches the base of the flap, and drives staples and/or sutures through it to secure the flap. The endoscopist engages additional portions of the fundus 46 and drives additional staples until the endoscopist is satisfied with the flap produced. While the pinch-and-staple procedure may provide a measure of treatment in appropriate hands, it neither fully restores the normal gastroesophageal flap valve anatomy nor produces a normally functioning gastroesophageal junction 52. Instead, the procedure only creates a tissue bulge that may assist in limiting reflux. Furthermore, this procedure is highly dependent on the skill, experience, aggressiveness, and courage of the endoscopist. A more timid endoscopist may take only small bites of tissue, and as a result may not successfully create a flap that functions as a normal movable flap 50. Every flap built with this procedure will be different because it depends so much on the skill and courage of the physician. Another transoral procedure contemplates making a fold of fundus tissue near the deteriorated gastroesophageal flap 55 to recreate the LES. The procedure requires placing multiple U-shaped tissue clips around the folded fundus to hold it in shape and in place. Like the previously discussed procedure, this procedure is also highly dependent on the skill, experience, aggressiveness, and courage of the endoscopist. In addition, these and other procedures may involve esophageal tissue in the repair. Esophageal tissue is fragile and weak, and involvement of esophageal tissue in the repair of a gastroesophageal flap valve poses unnecessary risks to the patient.
Present and emerging methods all depend on the skill, experience, and aggressiveness of the endoscopist to grasp the appropriate amount of stomach or esophagus tissue to build the depth and width of the structure contemplated. This results in non-uniformity from patient to patient and non-uniformity from endoscopist to endoscopist. There is a need for a highly standardized and uniform device and procedure for restoring the natural gastroesophageal flap valve and a normally functioning gastroesophageal junction.
In view of the foregoing, there is a need in the art for a new and improved apparatus and method for restoration of a gastroesophageal flap valve. The present invention is directed to a device, system, and method that provide such an improved apparatus and method for restoration of a gastroesophageal flap valve.